You can use the grid method. Draw a grid on the original, making the lines 1/2" apart. It's 4X6, so you would have a grid of 8X12 squares. You want to go from 4" to 16" so that's 4 times the original size. Now take a large piece of paper and draw the larger grid, which would be 2" squares.(take the 16X24 rectangle and divide it into 2" squares) Now take the little bit of the design in each of the 1/2" squares and transfer it to the larger square, going square by square. I looked for an example on line with pictures, but couldn't find one...